Research Projects
Speech recognition Manifold learning Optimization algorithms Dimensionality reduction Object recognition Computational biology

Multiplicative updates for convex optimization with non-negativity constraints

Many problems in neural computation and statistical learning involve optimizations with nonnegativity constraints. Examples include large margin classfication by support vector machines, density estimation in Bayesian networks, dimensionality reduction by nonnegative matrix factorization, and LTI filter estimation in acoustic echo cancellation. In this project, we have proposed a series of iterative algorithms where the optimization variables are multiplicatively updated from one iteration to another iteration. Those algorithms are very easy to implement and free of parameters to be tuned for convergence. And in practice, they converge fast to desirable solutions.

Related publications

1. Fei Sha, Yunanqing Lin, Lawrence K. Saul, and Daniel D. Lee. Multiplicative updates for nonnegative quadratic programming.Neural Computation, 19(8):2004-2031, 2007.  [ PDF ]
2. Fei Sha, Yonghahk Park, and Lawrence Saul.Multiplicative updates for L1- regularized linear and logistic regression.Advances in Intelligent Data Analysis VII: Proceedings of Seveth International Symposium on Intelligent Data Analysis (IDA 2007).Michael R. Berthold, John Shawe-Taylor, and Nada Lavrac. volume 4723 of Lecture Notes in Computer Science, pages 13-24. Ljubljana, Slovenia, 2007. Springer.  [ PDF ]
3. Fei Sha, Lawrence K. Saul, and Daniel D. Lee.Multiplicative updates for large margin classifiers. Proceedings of the Sixteeth Annual Conference on Computational Learning Theory (COLT 2003).B. Schölkopf, M. Warmuth. volume 2777 of Lecture Notes in Artificial Intelligence, pages 188-202. , Washington D. C., 2003. Springer.  [ PDF ]
4. Fei Sha, Lawrence K. Saul, and Daniel D. Lee. Multiplicative updates for nonnegative quadratic programming in support vector machines. Advances in Neural and Information Processing Systems 15.S. Becker, S. Thrun, and K. Obermayer. Cambridge, MA, 2003. MIT Press.  [ PDF ]
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Last Updated Oct. 20, 2008. Copyright © Fei Sha